Obviosity is used to describe a situation where a person lays a trap or tells a lie in earnest but the trap/lie is so obvious it's stupid.
1: A lie.
Guy 1: "I just killed twelve super dragons and made them into burgers." (An actual attempt at lying.)
Guy 2: "That statement is riddled with obviosty. You couldn't kill a super dragon if you tried AND there' only ten super dragons in existence."
2: A trap.
Guy 1: "Alright! The guard left his post for lunch and there's the top secret information just sitting there unlocked and unprotected."
Guy 2: "This is sooo obviosity"
when you're holding up your phone and making faces at it, as though you are taking a selfie, but you're really taking a picture of the person across from you or the wall or anything else that seems interesting but you don't want to be caught dead taking a picture of.
This action is often made more convincing by wiggling the eyebrows or opening the mouth, to pretend you're trying to get a Snapchat filter to work.
FRIEND A: "Did you just take a stealthie of me?"
FRIEND B (turning phone around): "no I was just using snapchat's new filter, see?"